I use Realtek High Definition Audio. In the Control Panal's Sounds and Audio Devices, Audio Sound Recording Stereo Mix is greyed out. It is greyed out in Realtek HD Audio Input, all of Audio Input is greyed out in Realtek and I don't have a mic. I want to
record with Stereo Mix but it is disabled. I looked at this link. http://www.niharsworld.com/2008/05/28/no-stereo-mix-recording-option-here-are-few-solutions/ and
doesn't help me. I know I could get a Audio Splitter but I don't want to do that. I tried looking in the Registry Editor for enabling Stereo Mix but couldn't find the thing for it. I have updated all my drivers. so does anyone know what I can do to get stereo
mix enabled and working ? I have searched internet already and no help. my last question about this a person told me , ---

"You may start the computer in a clean boot state and check if the issue persists. Clean boot helps eliminate any third party software conflict.

Note: After clean boot troubleshooting step, follow the “Steps to configure Windows to use a Normal startup state” in the provided link to return your computer to Normal startup mode.

Hope this information was helpful and do let us know if you need any assistance in the future regarding Windows. We will be glad to help."

This doesn't tell me anything at all. It's not any kind of conflict I know of. Windows XP and other systems have their Stereo Mix disabled. I cannot go into Sounds and devices thing and show my disabled devices to enable them like Vista users can.

That didn't help me any. I went to the link for the update but if you look at requirements it says,Supported operating systems: Windows XP Service Pack 2

I downloaded it and tried running it and it said, " KB935448 Setup Error , Setup has detected that the Service Pack version of this system is newer than the update you are applying. There is no need to install this update"

What can I do now ? Only thing I can think of would be to install Service Pack 2 then try the update and then come back to Service Pack 3 but that would be going back down to a earlier update. Is there any other way to fix it ?
If you look at the date from here, http://www.techsupportforum.com/forums/f23/resolved-stereo-mix-unable-and-cannot-be-enabled-162998.html That one is back during 2008/2009.

I don't know where I am suppose to look for the thing to fix it. On mine I want to record sound (Record What I Hear) known as Stereo Mix. I am recording with CamStudio from camstudio.org/ . I don't understand what to do from that link. Could you help me any ? It is greyed out in both Realtek and Windows XP recording settings.

On XP or earlier, right-click over the speaker icon in the System Tray > Adjust Audio Properties. Or you can click
Start > (Settings) > Control Panel > Sounds, Speech and Audio Devices > Sounds and Audio devices. If you then click on the Audio tab, you should see the following:

Did you get that far? If so, continue to follow the instructions on that page. AFAIK, "Stereo Mix" is shown as the input "Sum."

If that didn't help, then see this section of the page:

Sometimes "Stereo Mix" can only be made to work by using the control panel supplied by the sound card manufacturer - this is often reported with
RealTek inbuilt sound devices. Try launching the sound device control panel from the Windows Control Panel or the system tray (by the clock). If you see a volume control for Stereo Mix, try clicking to select it. Confusingly, some RealTek devices "select"
an input by muting all but one, so in this case, mute everything except stereo mix. If you don't see Stereo Mix, click the wrench icon and enable Stereo Mix in the dialogue that pops up. In some RealTek versions the option to check is
"Enabled recording multi-streaming". You should now see a volume control for Stereo Mix. Remember to select or unmute it as above. See this
Forum topic for more help with RealTek.

Be aware that on some machines, the "Stereo Mix" option will never work because it is disabled internally by the driver settings due to copyright concerns. This is a known issue with Lenovo Thinkpad laptops, but sometimes
editing the driver files can enable stereo mix.

If all else fails, you can connect a cable from the line-out (green) port of the computer to the line-in (blue), and choose the line-in as recording source. If you need to hear what you're recording, you can buy a single stereo to double stereo adaptor
that will give you a spare jack to plug the speakers into. Alternative suggestions follow below.

It didn't work for me. It is greyed out so I think it's internally disabled through driver settings.

I downloaded Audacity and it allows me to record audio with Stereo Mix. Thank you for helping. I can record whatever I hear with it with Stereo Mix and if I mute it in Realtek it won't record, but it still doesn't show up not greyed out in my Windows XP sound
settings or Realtek sound settings. What I mean by that is, I can see stereo mix in their after clicking "show volume controls " but can't adjust it or anything except click mute. So I cant adjust it that way or record from the Camstudio from speakers but
it's ok. thanks for replying back